Difference between revisions of "Operating Systems 2017F: Assignment 4"

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==Multiple Choice==
==Multiple Choice==


# To enable public key (password-less) authentication in ssh, a user's public key should be added to what file on the remote system?
<ol>
## /etc/passwd
<li>To enable public key (password-less) authentication in ssh, a user's public key should be added to what file on the remote system?
## ~/.ssh/authorized_keys
<ol>
## ~/.ssh/known_hosts
<li> /etc/passwd
## ~/.ssh/id_rsa.pub
<li> ~/.ssh/authorized_keys
# In ssh (on the Linux command line), in what file is a user's private key normally stored?
<li> ~/.ssh/known_hosts
# How do sshfs inode values relate to the inodes in the remotely mounted filesystem?
<li> ~/.ssh/id_rsa.pub
# What lines in memoryll determine the inode numbers?
</ol>
# In sshfs, do a file's uid and gid values come from the remote server or from the mounting user's uid and gid?
<li> In ssh (on the Linux command line), in what file is a user's private key normally stored?
# What permissions does a process require for regular file access?
<li> How do sshfs inode values relate to the inodes in the remotely mounted filesystem?
# In sshfs, what determines whether a file operation is allowed or not, the remote ssh daemon, the remote kernel, the local kernel, or the local ssh process?
<li> What lines in memoryll determine the inode numbers?
# When you run fusermount via execve, what euid does fusermount's process have?
<li> In sshfs, do a file's uid and gid values come from the remote server or from the mounting user's uid and gid?
# What environment variable allows ssh to connect to the local authentication agent?
<li> What permissions does a process require for regular file access?
# Why must ssh private keys only be readable by the owner?
<li> In sshfs, what determines whether a file operation is allowed or not, the remote ssh daemon, the remote kernel, the local kernel, or the local ssh process?
# How do you control how many bytes dd writes with each write system call?
<li> When you run fusermount via execve, what euid does fusermount's process have?
# When you make a write system call to a file on a sshfs-mounted filesystem, how many additional write (or writev) system calls must be executed, and what processes make those system calls?
<li> What environment variable allows ssh to connect to the local authentication agent?
<li> Why must ssh private keys only be readable by the owner?
<li> How do you control how many bytes dd writes with each write system call?
<li> When you make a write system call to a file on a sshfs-mounted filesystem, how many additional write (or writev) system calls must be executed, and what processes make those system calls?
</ol>

Revision as of 16:55, 3 December 2017

This assignment is not yet finalized.

Full Questions

  1. To enable public key (password-less) authentication in ssh, a user's public key should be added to what file on the remote system?
  2. In ssh (on the Linux command line), in what file is a user's private key normally stored?
  3. How do sshfs inode values relate to the inodes in the remotely mounted filesystem?
  4. What lines in memoryll determine the inode numbers?
  5. In sshfs, do a file's uid and gid values come from the remote server or from the mounting user's uid and gid?
  6. What permissions does a process require for regular file access?
  7. In sshfs, what determines whether a file operation is allowed or not, the remote ssh daemon, the remote kernel, the local kernel, or the local ssh process?
  8. When you run fusermount via execve, what euid does fusermount's process have?
  9. What environment variable allows ssh to connect to the local authentication agent?
  10. Why must ssh private keys only be readable by the owner?
  11. How do you control how many bytes dd writes with each write system call?
  12. When you make a write system call to a file on a sshfs-mounted filesystem, how many additional write (or writev) system calls must be executed, and what processes make those system calls?

Multiple Choice

  1. To enable public key (password-less) authentication in ssh, a user's public key should be added to what file on the remote system?
    1. /etc/passwd
    2. ~/.ssh/authorized_keys
    3. ~/.ssh/known_hosts
    4. ~/.ssh/id_rsa.pub
  2. In ssh (on the Linux command line), in what file is a user's private key normally stored?
  3. How do sshfs inode values relate to the inodes in the remotely mounted filesystem?
  4. What lines in memoryll determine the inode numbers?
  5. In sshfs, do a file's uid and gid values come from the remote server or from the mounting user's uid and gid?
  6. What permissions does a process require for regular file access?
  7. In sshfs, what determines whether a file operation is allowed or not, the remote ssh daemon, the remote kernel, the local kernel, or the local ssh process?
  8. When you run fusermount via execve, what euid does fusermount's process have?
  9. What environment variable allows ssh to connect to the local authentication agent?
  10. Why must ssh private keys only be readable by the owner?
  11. How do you control how many bytes dd writes with each write system call?
  12. When you make a write system call to a file on a sshfs-mounted filesystem, how many additional write (or writev) system calls must be executed, and what processes make those system calls?
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